Description:
A vulnerability was reported in Intel Core-based processors. A local user can obtain potentially sensitive information. Citrix XenServer is affected.

A local user can conduct cache side-channel attacks to exploit a flaw in the 'Lazy Floating Point Unit (FPU)' scheme where the kernel saves and restores FPU state during task switching to potentially determine FPU state bits.

System software that utilize the Lazy FPU state restore method to delay the restoring of state until an instruction operating on that state is actually executed by the new process is affected.